Archery bow with gyroscopic stabilizer



March 24, 1970 D. E. SHURTS ARCHERY BOW WITH GYROSCOPIC STABILIZER Filed Jan. 23, 1967 PIC-3.2

T H m MM N n vR m M U 0 C I GYROSCOPE GYROSCOPE INVENTOR DONALD E. SHURTS BY M ms ATTORNEY United States Patent 3,502,062 ARCHERY BOW WITH GYROSCOPIC STABILIZER Donald E. Shurts, 826 Shroyer Road, Dayton, Ohio 45416 Filed Jan. 23, 1967, Ser. No. 611,021 Int. Cl. F41b 5/00 U.S. Cl. 12423 2 Claims ABSTRACT OF THE DISCLOSURE An archery bow is provided having secured thereto a gyroscope having its axis of rotation capable of adjustment to different attitudes with respect to the bow.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to archery spring-bows used for projecting arrows, and particularly to adjustable poweroperated gyroscopic means for damping the tendency of the bow to kick, or deflect, in response to an archers grasp as the bow-string is released.

No prior art showing how to solve the problem is known except for the use of weights adjustably attached to the bow. The instant invention solves the problem by use of a running gyroscope adjusted as to its axial alignment with respect to the :base to counteract the archers personal muscular reaction to the bow-string release.

SUMMARY OF THE INVENTION The attachment of an electrically-powered gyroscope, secured to a limb of the archery bow at a distance from the archers grasp and in an axial attitude to overcome the archers produced torque, is provided. The gyroscope preferably should be of small dimensions and may be spaced sideways from the bow in any attitude to increase, by leverage, its effect. The turning torque operating upon the bow by the sidewise extension of the weight of the gyroscope and its attaching means may be compensated for by a counter-weight. The axial attitude of the gyroscope is adjustable by angular and sliding couplings to provide fully adjustable mean to custom-fit the equipped bow to the archer.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation of an archery long bow with the gyroscope in place in an exemplary attitude.

FIG. 2 is a detail of typical mounting brackets and supports by which the gyroscopes attitude may be adjusted with respect to the bow.

DESCRIPTION OF PREFERRED EMBODIMENT This invention relates to an adjustable archery bow stabilizer, and more particularly pertains to such a stabilizer employing a gyroscope affixed to the bow at such an attitude that, when running, it will be inertial and precessional action, damp the tendency of the bow to twist or deflect as a drawn bow string is released while the bow is hand-held in the archers grasp.

The prior art has disclosed the use of weights attached to the bow to give an extra moment of inertia to the bow system, but I have found that a running gyroscope, adjustable as to attitude, will give, when spinning at effective speed, a profound damping effect to archer-applied forces subsequent to string release without increasing the weight of the system to any marked degree.

The gyroscope, preferably of the electric-motor-driven type, is so mounted that the axis of rotation of the gyroscope can be adjusted to any attitude to suit the dynamics of the bow reaction upon string release in the hands of a particularly archer. While the electricallydriven gyroscope is preferred, it is within the scope of the invention to have it driven by an conventional means, such as a spring-operated motor, an air turbine, a water turbine, or mere inertial cranking by a crank or by a string wound around the axis. Usually, and preferably, the mounting clamp is to be fastened to the lower limb of the how, about half-way to the tip, with the gyroscope axis of rotation parallel to the plane traversed by the arrow released from the bow string from a drawn position, and pointed generally in the direction of arrow flight. The axis of rotation may be positioned to the left or the right side of the bow, if desired, to accommodate to a right-handed or a left-handed archer, as the case may be, or it may lie on the plane of the bow string movement and arrow trajectory if they are the same. A side displacement of the gyroscope to one side or the other of the plane of bow string movement seems by the resulting leverage to have greater effect in resisting sudden bow kicking, but such displacement sideways will be at the expense of static imbalance of the bow system unless a counter-weight is employed.

I provide adjustable mounting devices by which any of the adjustments of the gyroscope mountings may easily be made to fit the bow to the archer.

To illustrate the invention, I have supplied a drawing, in conjunction with which the invention will be described.

Referring to the drawing, there is attached to the bow 10, equipped with a bow string 11, a clamp 12 having ears 13 and a thumb screw 14 for securing the clamp to either limb of the bow. Preferably, the clamp is positioned on the lower limb of the bow, where the gyroscope motor wires 15 are convenient to an electric power source 16, disclosed conventionally as a battery 16. Placement of the gyroscope system on the lower limb gives a pendulum effect more conducive to static stability than if it were on the upper limb.

Mounted pivotally in a boss 17, projecting from the clamp, is a support stud 18, whose angular attitude is held in an adjusted position by a set-screw 19 and in which stud is slidably mounted a rod 20, held in position by a set-screw 21. To one end of the rod 20 is secured a counter-weight 22, and at the other end is a collar 23, set in place axially and radially by a screw 24. Projecting radially from the collar 23 is a gyroscope housing support rod 25, having secured thereto the mounting case 26 of an electrically-driven gyroscope having its axis of rotation 27 (FIG. 2) in line with the rod 25 and maintained in such relation by the housing. The adjustment means shown give entire freedom to orient the gyroscope to the needs of a particular archer, as the kick given to the bow on the string release depends on the grasp, which in turn is determined by the archers musculature and innervation.

Both the inertial and precessional vector forces of the gyroscope are of use.

Once set to a particular archer and bow system, the attitude and placement are maintained for the period of use.

The gyroscope mass, inertial and precessional factors, and attitude all may be selectively determined for a given bow system, but the total weight of the gyroscope and the mounting should be kept at a minimum.

The principle of the invention has been shown applied to a simple long how, but the mechanism may be applied to string bows of all shapes, weights, and dimensionsfor rightor left-handed archers, and for all bow attitudes.

The gyroscope is of the fixed axis type, run by a miniature motor, preferably an electric motor capable of being operated from electric dry cells carried in the archers pocket. When set running and fixed relative to the target, the gyroscope will effectively and dynamically damp the kicking of the bow system on string release.

What is claimed is:

1. An archery bow having secured to it, by adjustable securing means, a gyroscope having its rotational axis in selected fixed relation to the bow.

2. The bow of claim 1 in which the gyroscope is electrically operated.

References Cited UNITED STATES PATENTS 3,006,197 10/1961 Kenyon et al. 745 XR 4 3,196,860 7/1965 Hoyt 12424 1,892,209 12/1932 Fisher 124-19 FOREIGN PATENTS 5 586,825 4/1947 Great Britain.

OTHER REFERENCES Accra-Lizer, Archery Magazine, vol. 34, August 0 1962, p. 35.

US. Cl. X.R. 

